Interfacial Templating of Inorganic Nanostructures Using Rationally Designed Peptide Molecules
Item
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Title
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Interfacial Templating of Inorganic Nanostructures Using Rationally Designed Peptide Molecules
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Identifier
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d_2009_2013:0f69ccba2401:10965
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identifier
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11329
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Creator
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Leon Gibbons, Lorraine,
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Contributor
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Raymond Tu
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Date
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2011
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Language
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English
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Publisher
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City University of New York.
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Subject
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Chemical engineering | Materials science | Nanotechnology | Biomaterial | Crystallization | Peptide | Self-Assembly | Templating
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Abstract
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In nature, biological molecules form interfaces that assemble patterns of chemical functionality with exceptional precision. The role of dynamics during the assembly of biological molecules appears to be important for mineralization processes. The work presented in this dissertation applies model sheet-forming peptides at interfaces to explore the dynamics of assembly in order to template mineral growth. The peptide molecules are rationally designed to have amphiphilic properties and a propensity for sheet-like secondary structure. These designed peptides are deposited at the air/water interface to explore the dynamics of their self-assembly and investigate their 2D order. To characterize the phase behavior, techniques such as Langmuir Blodgett and Brewster Angle Microscopy are used. In addition, we verify the hypothesized sheet-forming propensity using both Circular Dichroism and Attenuated Total Reflection Fourier Transform Infrared Spectroscopy, while the characterization of the inorganic phase is done using Transmission Electron Microscopy, Electron Diffraction, and Atomic Force Microscopy.;Thermodynamic analysis of structure formation with increasing pressure allows us to understand the nature of self-assembly with iterative changes in the peptide sequence. Additionally, we look at the dynamics of the self-assembled state, where the organic phase switches between short- and long-range order as a function of surface pressure. We use this model system to explore the influence of electrostatic interactions on self-assembly, and additionally, the influence of short- and long-range order on the nucleation and growth of inorganic material. This is in contrast to a system that starts with a well-ordered preformed template that defines the epitaxial growth of the mineral phase. Two versions of our model peptides are constructed by substituting histidine for glutamic acid in order to nucleate Au nanocrystals in both the short and long range ordered organic matrix, to show that the phase behavior of the peptide influences the crystallinity and shape of the templated nanocrystals.
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Type
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dissertation
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Source
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2009_2013.csv
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degree
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Ph.D.
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Program
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Engineering
